Reciprocating piston compressor



Oct. 11, 1960 R. J. HACKBART ETAL 2,955,751

RECIPROCATING PISTON COMPRESSOR Filed Aug. 26, 1958 v N 3 :8 i

2 Sheets-Sheet 1 FIG. 5

O d m INVENTOR.

REUBEN J. HACKBART EMIL T. NEUBAUER cu-- BYWVM ATTORNEYS Oct. 11, 1960R. J. HACKBART ETAL 2,955,751

RECIPROCATING PISTON COMPRESSOR v Filed Aug. 26, 1958 2 Sheets-Sheet 2INVENTOR. REUBEN J. HACKBART EMIL T. NEUBAUER BY FIG 3 38 My QMATTORNEYS United States Patent RECIPROCATING PISTON COMPRESSOR Reuben J.Hackbart, La Crosse, Wis., and Emil T. Neubaner, Sidney, Ohio, assignorsto The Trane Company, La Crosse, Wis., a corporation of Wisconsin FiledAug. 26, 1958, Ser. No. 757,326

'4 Claims. (Cl. 230-187) This invention relates to a reciprocatingpiston compressor and more particularly to a multi-cylinderreciprocating compressor in which the angularly adjacent cylinders ineach row of cylinders are staggered a fixed determined distance from oneanother in the axial direction of the crankshaft.

An object of this invention is to provide a compact multi-cylinderreciprocating compressor which is economical to manufacture and easy toassemble.

Another object of the invention is to provide a reciprocating pistoncompressor with the same capacity and number of cylinders ascontemporary compressors but which is smaller, more compact, lighter,and cheaper to manufacture.

The third object of the invention is to provide a compact multi-cylinderreciprocating piston compressor which has the cylinders staggered toallow the cylinders to be placed closer to the crankshaft in order toreduce the size of the compressor housing and the length of theconnecting rods.

A further object of the invention is to provide a multicylindercompressor with a two-throw crankshaft in which the angularly adjacentcylinders connected to each throw are staggered a fixed determineddistance from one another in the axial direction of the crankshaft.

A still further object of the invention is to provide an eight cylinder,two-throw refrigeration compressor in which the cylinders connected toeach throw are staggered at least two connecting rod widths in the axialdirection of the crankshaft from the next angularly adjacent cylinderconnected to the same throw.

Other objects and advantages of the invention will be clearly apparentas the specification proceeds to describe the invention with referenceto the accompanying drawings in which:

Fig. 1 is a roll out view of the cylinder banks of an eight cylindercompressor with the connecting rods shown schematically;

Fig. 2 is a section view on line 2-2 of Fig. 1 showing one row ofcylinders as they appear around the periphery of the compressor housing;

Fig. 3 is a section view through one bank of cylinders in the compressorshowing the cylinders in operative position; 7

Fig. 4 is a diagrammatic roll out view of ten cylinder compressor; and

Fig. 5 is a diagrammatic roll out view of a twelve cylinder compressor.

Previous to our invention, the cylinder rows of a reciprocating pistoncompressor were normally spaced around the periphery of the housing in aspiral configuration with each adjacent cylinder in each row spaced fromone another one connecting rod width in the axial direction of thecrankshaft. The result of which was that compressors having the samenumber of cylinders, bore, and stroke would necessarily have a limitingsize which is determined by the minimum radial distance of the cylindersfrom the axis of the crankshaft. This minimum distance being from thepoint where the operation of one cylinder does not interfere with theoperation of any of the other cylinders in the compressor.

Our improved cylinder arrangement is applicable to reciprocating pistoncompressors of eight cylinders or more. For the sake of clarity anddisclosure, an eight cylinder refrigeration compressor will be discussedholding in mind that the invention is applicable to other reciprocatingpiston compressors within the scope of the claims.

5 Referring now to Fig. 1, cylinders 12, 14, 16, 18, 20, 22, 24, and 26of compressor 10 with cylinder liners 11, 13, 15, 17, 19, 21, 23, and 25therein respectively are shown schematically connected to throws 28 and30 of compressor crankshaft 32 by means of connecting rods 34.

Our new cylinder design encompasses staggering of the cylinders in orderto allow the cylinders to be located closer, in the radial direction, tothe crankshaft 32 in order to reduce the size of the compressor and someof the component parts. The staggering of cylinders is accomplished bydesigning the compressor housing so that the axial centerlines ofangularly adjacent cylinders in each row are separated from one anotherin the axial direction of the crankshaft by at least a distanceequivalent to A two connecting rod widths. This staggering of thecylinders is maintained by connecting the adjacent connecting rods ofeach throw to cylinders which are spaced two are angles apart. One arcangle being the angle between two adjacent cylinders in the same row.For example, the arc angle of the eight cylinder compressor is 45. Itshould be noted that maintaining the adjacent connecting rods on eachthrow two arc angles from one another will not space the connecting rods34 adjacent the crank web 35 two are angles apart. The requiredstaggering of the cylinders is maintained by making the center crank Web35 between the throws at least two connecting rod widths apart so as tomaintain a minimum distance between angularly adjacent cylinders.

As an example of the above, cylinders 20 and 22 are connected to thefirst connecting rods on throws 28 and 30 respectively, and cylinders 24and 26 are connected to the third connecting rods on throws 28 and 30respectively. Then necessarily, cylinders 12 and 16 will be connected tothe remaining connecting rods on throw 28 and cylinders 14 and 18 willbe connected to the remaining connecting rods on throw 30. The disclosedarrangement is merely exemplary and other designs are feasible withinthe scope of the invention as long as the axial distance betweenadjacent cylinders in each row is at least two connecting rod widths.Note that the adjacent connecting rods 34 on each throw connect thecrankshaft to cylinders which are spaced from one another at least twoarc angles from one another. As an example, the connecting rodsconnecting cylinders 22 and 14 are spaced from one another through anangle of which is equivalent to two are angles of 45.

As is well known in the art, the cylinders of each row of cylinders arespaced around the periphery of the cornpressor housing 36 as shown inFig. 2 with the centerline of cylinder 14 being located 22 /2 clockwiseof a line perpendicular to the axis 28 of the crankshaft 32 and parallelto the base 38 of the. compressor 10. The centerlines of cylinders 18,22, and 26 are spaced 45, 90, and respectively, clockwise around theperipher of the compressor housing 36 from the above mentionedcenterline of cylinder 14. Cylinders 12, 16, 20, and 24 are also spacedin like manner around the upper half of the circumference of thecompressor housing 36. The cylinders are so spaced so as to lessen thepossibility of slugging which would increase if some of the cylinderswere located in the lower half of the compressor housing 36.

As discussed above, there is a minimum radial distance between thecrankshaft and the cylinder which must be Patented Oct. 11, 196d order hre re. th Q lYW Y. w 'lh 25 3 pressor is todesignaconipre'ssorwhichallowsjthe ers tojae placed closer in a radialdirection [to the. crankat" I fig. 2, n can be seminar die-staggeredrelationship oft-he cylinders allows the cylinder liners to overlap oneanother in order to be able to project the cylinders radially closertotlie crankshaft, the greater the distance between angularly adjacent'cyl n; ders', the closer to crankshaft .the cylinders may in the radialdirection. Therefore, since by connecting rodrwidthsiapart, we haveprovided a cylinder design which is smaller and more eompact thancontemporary compressors since 'chntempora ry compressors provide onlyone connecting rod width between cylinders The operation of the compessor is typical and not part of the invention. In Fig, 3 it can be seenthat when the pistons 39 descend on the suction strokethat gaseousrefrigerant and oil are drawn through suction memo, through uctionstrainer 42, and chamber From suction manifold the ageing gases aredrawn through suction'po'rts 46 into compression chqarnberfls.

On the compression stroke, the gaseous refrigerant is compressed anddischarged into discharge chambers 50 The compressed refrigerant is thencollectedin manifold chamber 52 and directed to the pointof Figs. 4 and5 represent diagrammatic'roll outyiews er a ten and a twelve cylinderreciprocating eqmpr'ess r with cylinders located in accordance with ourinve Figs. 4 and 5 are similar to that of Fig. 1 wherein the {r'ert'icallines represent the axis of 'the'bank's or cylinders and the horizontallines represent 'the axis of the coin necting rods. Obviously, thedistance between horizontal lines represent connecting rod widths andthe distance between vertical lines represents arc angles betweencylinders. Dots 54 represent cylinders and reference number 320represents the crankshaft location, i q 4' and 5 are merely showntoillustrate that staggered cylinderof our invention is applicable toother compressors of different size and not merely restricted to ,aneight cylinder compressor.

Q Our above disclosed compressorfis smaller, inore com: pact, andcheaper to manufacture than contemporary compressors of thesamefcapacity. O ur compressor comparison with other compressors withthe same humb'r of cylinders,tcapacity, stroke, and bore will have;on1pressor housing of smaller diameter, lighter weights, and shorterconnecting rodsn 0bv'iously, the above improvements result in a lighter,cheaper, and more compact compressor. Further, our"compressor niay usedin applications where size is paramount and other compressors may 'notbe used. Also, our compressor allows us to reduce the size of anypackaged air condition iiig equipment in which we desire to use theabove dis elosjed comp-ressor. Finally, our fiew'and improved coniso'rallows us to compete successfully against con temporary compressor's'dueto lwer cost of production lower-shipping costs which result from thereduction of ivfeight'and size of component parts. j V I Although wehave described in detail the preferred embodiments of our invention, wecontemplate that many changes may be made without departing from thescope or'spirit of our invention, and we desire to be limited onlybyjthe claims. a a

into suction ,manifoljd w aim V 1. A compressor comprising; a housing, afirst row of four cylinders and a second row of four cylinders in theupper half of said housing with the axes of adjacent cylindcrs in eachof said rows having an arc angle therebetw'een said arc angles betweenadjacent cylinders in each row being substantially equal, a 'erankshafthaving a first throw andv a second throw -rotatably supported by saidhousing suhs't an'tiaHy perpendicular to the aiies of said cyl'iiiiiers,pisto n meansslidably supported in said cylinder sfo'ur connecting rodsrotatably connected a't one end to said first throw and operablyassociated with said piston means ofsaidfirstrow at'the other end, andfour connecting rods rotatably connected at one end to said second throwahd ope'rably associated with said piston means of said second row atthe other end, the adjacent connecting rods on each throw beingconnected to piston rneans'whose ages are separated by atleast twoarcangles whereby the of adjacent cylinders in 'eachfrow are eis'p'aearram me another in theaxial dir'ctionfof the aidist'ance at leastequal to the width of two co n'nectihg V I 2. The structure of claim 1wherein'the cylindersin V saidfirst row are in alignment in the axialdirection of the crankshaft with thev corresponding cylinders in saidsecohdrbwf ti v ii Acompressor comprising; a housing, at ,least one rowrema n e in the upper half of said housing with of adjacent cylinders insaid one row having re angle therebetween, saidarc angles between adjacent cylinders in said one row being approximately 45f, a crankshaftrotatablysupported by said housing subperpendicular to the axes of saidcylinders was w s w sa r se 'm enef d portedin said cylinders, and fourconnecting rods rotats l,

associated with said piston means of said one row at the other, endwithadjacent connecting rods on said one "to piston meanswhose axes 'areseparated by at least two arc angles whereby the axes of ladjacentcylinders in said one row are displaced from one another axialdirectionof the crankshaft a distance at least equal to the width of twoconnecting rods. 7

t. compressor comprisingya housing, at least one row f fo ur cylindersin the upper half of said housing with the axes of adjacent cylindersin'saidone rowhaving an arc angle therebetween,-said arc angles betweenadjacent cylinders in said one row being substantially'equal, a crank;shaft rotatably supported by said housing substantiallyperpendicularlto'the aires of said cylinders having at least one throw,piston means slidablysl'lpp cdin said cylindersand fourconnecting rodsrotatably conaxis $1 atxmesnsl f a d. v rqw n p y we ciated with saidpiston means of said one row 'atthe other end I with adjacent connectingrods on said one throw being connecl'tedto piston meanswhose axes areseparated I by at lea st two arc, angles whereby the axes of adjacentcylinders in said one row are displaced 'fromone another intheaxialdirection of the crankshaft a distance at least equal to thewidth of two connecting rods.

References Cited in the file of this patent 7 UNITED STATES "PATENTS1,2,6,7,92 9 .r stevens May '28, 1918 71,395,151, Wheeler Nov, s, 1921FOREIGN PATENTS V 229,3 0 ermany July 9., .1969

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